Multiple chamber incinerator

ABSTRACT

A grateless incinerator having a pair of combustion chambers including a primary chamber and a secondary chamber separated by a movable closure means. Incineration is started in the primary combustion chamber, then ash including unburned residual matter is dropped from the primary chamber through the movable closure means to the secondary chamber which is located subjacent thereto. Smoke and gas generated by continuing combustion of the incompletely burned residual matter is returned through a controlled passageway to the incinerator downstream therefrom whereby it is again subjected to incinerating temperatures before it is directed through an exhaust duct to the atmosphere.

a United States Patent Liu et al. Apr. 30, 1974 [54] MULTIPLE CHAMBERINCINERATOR 3,330,230 7/ 1967 Sasaki 1 10/17 [75] Inventors: g gsg gzg biz' Lubertus Primary Examiner-Kenneth W. Sprague Attorney, Agent, orFirm-Wayne H. Lang [73] Assignee: The Air Preheater Company, Inc.,

Wellsville, N.Y. [57] ABSTRACT [22] Filed: Jam 16, 1973 A gratelessincinerator having a pair of combustion Appl. No.: 324,011

chambers including a primary chamber and a secondary chamber separatedby a movable closure means. Incineration is started in the primarycombustion chamber, then ash including unburned residual matter isdropped from the primary chamber through the movable closure means tothe secondary chamber which is located subjacent thereto. Smoke and gasgenerated by continuing combustion of the incompletely burned residualmatter is returned through a controlled passageway to the incineratordownstream therefrom whereby it is again subjected to incineratingtemperatures before it is directed through an exhaust duct to theatmosphere.

8 Claims, 2 Drawing Figures MULTIPLE CER INCINERATOR BACKGROUND OF THEINVENTION 1. Field of the Invention The invention relates to a devicefor the incineration of waste material. The device includes anincinerator including an enclosed primary combustion or pyrolyzingchamber, a subjacent secondary combustion chamber, and an afterburner.The secondary combustion chamber is closed except for a source of airand fuel for combustion and an exhaust duct connected back to theincinerator whereby smoke and other gaseous matter generated therein mayagain be subjected to high combustion temperatures before it isexhausted to the atmosphere.

2. Description of Prior Art While it is common knowledge that amultichambered incinerator constructed to include a controlledpyrolyzing chamber together with an afterburner comprises a commonarrangement for eliminating organic waste, the effective operation ofsuch apparatus requires complete pyrolyzation of waste and then completecooling of the pyrolyzing chamber before the incinerator may be openedto the atmosphere and the ash manually removed therefrom in the mannershown by U. S. Pat. Nos. 3,491,707 and 3,505,181.

In these patents, the incinerator comprises a housing enclosing agrateless combustion chamber that effects the pyrolyzation of organicwaste thereinand having in combination an afterburner that is connectedto the housing exhaust to burn the gases given off therefrom. Pyrolyzation of waste may continue for some time, but when periodicallycharging with waste material the loading door must be opened so that thecontrolled atmosphere in the pyrolyzing chamber altered, and theconditions of pyrolyzation thus terminated. Moreover, pyrolyzation mustbe halted periodically to permit a cool-down of the chamber sufficientto allow it to be manually opened and the accumulation of ash removed.Furthermore, conventional metallic grates can not be used in hightemperature zones as their longevity requires the continuous flow ofcooling air in a manner not avilable in a controlled atmosphereincinerator.

SUMMARY OF THE INVENTION It has been found that when incinerating anormal mix of organic waste and trash the completion of a normal burningcycle of operation may require from six to eight hours time, although 90percent of the waste.

1 charge may be burned during the first hour or so of operation.Therefore, most of the burning time is required to dispose of but asmall part of the unburned residual matter, by far the largest portionof the waste being disposed of during the first moments of operation.

The present invention therefore relates to a controlled air pyrolyzingor starved air type incinerator of are ducted back into the incineratorwhere final com-,

bustion is effected so only carbon dioxide, water and some metallicfumes are exhausted into the atmosphere.

BRIEF DESCRIPTION OF THE DRAWING A better understanding of the inventionmay be had by reference to the drawings in which:

FIG. 1 is a sectional elevation of my invention.

FIG. 2 is a line graph that shows the reduction in volume of a charge inan incinerator as viewed with respect to time.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings of the presentinvention the reference numeral 10 designates a housing enclosing apyrolyzation or primary chamber 12 having an access door 14 for theloading of waste material therein and an outlet opening 16 for theexhaust of gaseous products from the pyrolyzation chamber.

Connected to the outlet opening 16 is a duct 18 that encloses anafterburner chamber 22 and exhausts through a stack 24 to theatmosphere. I

A source of air 26 is directed through line 28 to the pyrolyzationchamber 12 through line 32 to the afterburner 22 having respectivelycontrol valves 30 and 33 whereby gases generated in chamber 12 may beprovided with adequate air for the pyrolyzation of the waste in chamber12 and complete burning of the pyrolyzed gases in the afterburner. Aseparate source of fuel is provided to the afterburner through line 34and controlled by valve 57 whereby temperatures therein may be mintained at frqm 12 09519200? adlbm sh line 55 controlled by valve tochamber 12 whereby the temperature therein may preferably range from 500to 1,500 F. depending upon the charge in chamber 12. The valves in theair and fuel supply lines may be manually controlled or they may bethermostatically controlled in a manner that is now well known in theart and shown by U. S. Pat. No. 3,491,707.

The bottom of the chamber 12 has a movable closure 36 that comprises asingle or multiple door arrangement that effectively seals primarychamber 12 from a subjacent secondary chamber 38. The movable closure isformed of ceramic or other heat resistant material and is provided witha suitable arrangement such as hydraulic actuator 42 pivoted to anextension 49 on the closure 36, whereby the closure may be inclined asdesired to permit any material thereon to slide down to the secondarychamber 38.

A connecting duct 44 joins chamber 38 to the primary chamber 12 and tothe afterburner 22 wherein gases from chamber 38 may be selectivelydirected to chamber 12 of the afterburner 22. Suitable valves 45 and 47make possible the opening and closing of the connecting branch ducts totheir respective chambers.

A mechanical collector 51 having valve means 52 through which airaccumulation of particulate matter may be removed is included in theconnecting duct 44 whereby large particles of ash entering duct 44 aredirected through collector 51 and immediately removed from the carriergas so they are not passed through duct 44 and permitted to erode theduct and its control valves 45 and 47.

As the ash and other residual matter falls from chamber 12 to secondarychamber 38, agitation may produce a cloud of particulate matterincluding smoke and ash that accompanies the smoke produced by theunburned particulate matter. At this time valve 47 is closed and valve45 is opened so that the gases carrying particulate matter will bedirected back into chamber 12 which now serves as a settling chambertherefor.

Thus, upon entering chamber 12 the small particles of 5 particulatematter will drop to the bottom of the housing and gaseous material alonewill exhaust to the afterburner chamber 22 and the outlet stack 24.Inasmuch as combustion is closely controlled in chamber 12 by regulatingvalve 30 in the air duct 28 and valve 50 in fuel line 55, the delicateconditions of pyrolyzation therein may be further upset by directingexhaust gases including combustible gases and air back into chamber 12through duct 44. Therefore, after residual matter has been dumpedthrough closure 36, the ash has settled, and after a burn of a newcharge in chamber 12 has been initiated, valve 45 may be closed andvalve 47 to the afterburner opened so that exhaust from chamber 38 nowincluding air and fuel is not directed back into chamber 12 to. upsetconditions of pyrolyzation there, but is ducted directly to afterburner22 for high temperature incineration and then via stack 24 to theatmosphere.

An ash clean-out door 43 is provided in the secon- I dary incineratorchamber 38 to permit an accumulation of ash to be periodically removed,generally at a time when the entire incinerator is shut down. However,by closing valves 39 and 47 for the air and fuel, the valves 45 and 47for the exhaust gases, the chamber 38 may be completely isolated fromthe rest of the incinerator whereby the door 43 may be opened at anytime without upsetting conditions in the rest of the incinerator.

In operation, rubbish, garbage and other carbonaceous material is loadedinto the incinerator chamber 12 through loading door 14. Ignition isstarted therein by any suitable method such as simply opening fuel valve50 and applying a lighted match to the flowing fuel. The flow of airfrom source 26 is started and controlled by opening valve 30 asrequired, and as the waste material in the incinerator burns, gas andsmoke generated in chamber 12 is exhausted through exhaust port 16 toafterburner chamber 22.

Excess air added to the afterburner 22 through duct 32 and fuel addedthrough 34 causes complete combustion of all pyrolyzed gas and smokegenerated in chamber 12 so only residual gases and smoke are exhaustedthrough stack 24 to the atmosphere.

In a burn that normally takes six to eight hours for completion,approximately 90 percent of a total charge in an incinerator is burnedin the first hour, the remaining five to seven hours being required toburn the remaining 10 percent of the charge in the manner shown by graphof FIG. 2.

Accordingly, incompletely burned residual matter and ash from chamber 12is dumped through opened closure 36 by means of actuator 42. After beingopened momentarily to permit residual matter to pass therethrough, theclosure 36 is quickly closed so that a new charge of waste material mayimmediately be loaded through opening 14 and combustion thereof maybeinitiated.

The incompletely burned residual matter in chamber 38 continues tosmolder and smoke, but the by-pass duct 44 now directs the exhausttherefrom through collector 51 to the chamber 12 where it is immediatelymixed with the hot gases therein and passed through port 16 to theafterburner 22 where the hydrocarbons are completely incinerated beforebeing exhausted to the atmosphere. Conditions suitable for limitedcombustion are maintained in chamber 38 by supplying air through supplyline 35 as controlled by valve 39, and

fuel from source 37 as controlled by valve 41 whereby not shown in thedrawing, it should be understood that conventional thermocouples in theseveral chambers may be used in the manner illustrated by U. S. Pat.Nos. 3,491,707 and 3,595,181 without departing from the spirit of theinvention.

It is therefore intended that all matter contained in the abovedescription or shown in the accompanying drawings shall be interpretedas illustrative and not in a limiting sense.

We claim:

1. An incinerator for burning combustible waste material comprising aprimary combustion chamber having an inlet opening for the admission ofwaste material and an outlet opening for the exhaust of gases generatedtherein, an outlet stack having an afterburner, means connecting theoutlet stack to the outlet from the primary combustion chamber, asecondary combustion chamber subjacent the primary combustion chamber, asource of air for combustion supplied to the primary and secondarycombustion chambers, movable closure means separating the primarycombustion chamber from the secondary chamber, means for actuating themovable closure means, and duct means interconnecting the secondarycombustion chamber and the incinerator downstream therefrom whereby gasand particulate matter generated in the secondary combustion chamber maybe directed back into the incinerator to be subjected to furtherincineration.

2. An incinerator for burning combustible waste material as defined inclaim 1 wherein the means that connects the secondary combustion chamberand the incinerator downstream therefrom comprises a duct between theprimary and the secondary combustion chambers. 1

3. An incinerator for burning combustible waste material as defined inclaim 1 wherein the movable closure comprises a partition that isolatesthe primary from the 1 terial as defined in claim 1 including meansbrojecting cooling water into the secondary combustion chamber,

a source of water, and means regulating the flow of water from thesource of the secondary chamber.

1. An incinerator for burning combustible waste material comprising aprimary combustion chamber having an inlet opening for the admission ofwaste material and an outlet opening for the exhaust of gases generatedtherein, an outlet stack having an afterburner, means connecting theoutlet stack to the outlet from the primary combustion chamber, asecondary combustion chamber subjacent the primary combustion chamber, asource of air for combustion supplied to the primary and secondarycombustion chambers, movable closure means separating the primarycombustion chamber from the secondary chamber, means for actuating themovable closure means, and duct means interconnecting the secondarycombustion chamber and the incinerator downstream therefrom whereby gasand particulate matter generated in the secondary combustion chamber maybe directed back into the incinerator to be subjected to furtherincineration.
 2. An incinerator for burning combustible waste materialas defined in claim 1 wherein the means that connects the secondarycombustion chamber and the incinerator downstream therefrom comprises aduct between the primary and the secondary combustion chambers.
 3. Anincinerator for burning combustible waste material as defined in claim 1wherein the movable closure comprises a partition that isolates theprimary from the secondary combustion chambers.
 4. An incinerator forburning combustible waste material as defined in claim 1 wherein themeans connected to the outlet of the primary combustion chambercomprises a passageway intermediate the primary combustion chamber andafterburner.
 5. An incinerator for burning combustible waste material asdefined in claim 1 wherein the duct means comprises a branched ductconnecting the secondary combustion chamber to the primary combustionchamber and the afterburner.
 6. An incinerator for burning wastematerial as defined in claim 4 wherein the branched duct includes valvemeans adjacent the primary combustion chamber and the afterburner tocontrol gas flow therethrough.
 7. An incinerator for burning combustiblewaste material as defined in claim 1 including an ash cleanout door inthe secondary combustion chamber.
 8. An incinerator for burningcombustible waste material as defined in claim 1 including meansprojecting cooling water into the secondary combustion chamber, a sourceof water, and means regulating the flow of water from the source of thesecondary chamber.